/Engine/Source/Runtime/Slate/Public/Framework/Docking/TabManager.h
Finds the first instance of an existing tab with the given tab id.
The existing tab instance if found, otherwise null.
[TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [SDockTab](API\Runtime\Slate\Widgets\Docking\SDockTab) > FindExistingLiveTab ( const [FTabId](API\Runtime\Slate\Framework\Docking\FTabId) & TabId ) const